1. Field of the Invention
The invention relates to an inkjet printer which performs recording by ejecting ink droplets from nozzles arranged in a nozzle surface onto a recording medium by driving an actuator, and more particularly to an inkjet printer including an IC chip having a drive circuit for driving an actuator and disposed near rows of nozzles.
2. Description of Related Art
In a conventional inkjet printer, drive signals transmitted to an actuator are modulated depending upon the temperature of an environment in which the printer rests or is used (hereinafter referred to as “an environmental temperature”), in order to prevent degradation in the print quality due to a variation in the temperature of ink supplied to be ejected from nozzles in the form of droplets. Further, there has been proposed in Japanese Patent Application Laid Open No. 9-239989, a method in which a value to which the temperature of an inkjet printhead will rise after printing is complete throughout a given unit print area defined in a recording medium is estimated or calculated before the printing is actually performed, based on print data indicative of an image to be printed within the print area, more specifically, the total number of dots constituting the image, and when the result of the calculation indicates that there is a possibility for degradation in the print quality, the printing is implemented with a part of the print data masked.
Meanwhile, there have been recently an increasing demand for increasing the density of arrangement of nozzles in the nozzle surface of an inkjet printhead, for enhancing the resolution at which images are printed, and a tendency of downsizing a carriage or head holder holding the inkjet printhead so as to miniaturize an inkjet printer as a whole. The enhancement in the resolution increases an amount of heat generated at the printhead, while the downsizing the head holder necessitates an arrangement where an IC chip (or a drive circuit for driving an actuator) which generates heat is disposed in the vicinity of the printhead. As a consequence, a variation in the temperature of the printhead occurs, namely, the temperature of the printhead varies from place to place depending upon the relative position with respect to the IC chip, that is, depending upon the distance from the IC chip. This variation in the temperature of the printhead may cause an undesirable variation in printing characteristics among the nozzles depending upon their position relative to the IC chip.